Moving stairway



April 4, 1939. J. DUNLOP MOVING STAIRWAY Filed Jun 26, 195'? NVENTOR O/mes Dun/0,0.

ATT

WITNESSES:

Patented Apr. 4, 1939 UNITED STATES PATENT OFFCE MOVING STAIRWAY `laines Dunlop, kPark Ridge, Ill., assigner to Westinghouse Electric Elevator Company, Chicago, Ill., a corporation of Illinois Application June 26, 1937, Serial No. 150,492

3 Claims. (Cl. 198-16) My invention relates to moving stairways and of end bars I2 and I3, a pair of leading rollers I4 more particularly to the steps embodied therein. and l5 and a pair of trailing rollers I and I'l.

My application Serial No. 198,867, led March The step tread Ill may be constructed of any 30, 1938, is a division of this application. suitable material, preferably or molded fibrous 5 One object of my invention is to provide a movmaterial, with a heat hardened binder, and it may 5 Ving stairway step which shall be simple and ecobe constructed in a plurality of sections or in one nomical to manufacture and which shall be quiet complete section provided with a plurality of and easily maintained in operation under varying cleats I9 disposed on its upper surface to provide a conditions. plurality of grooves 2|). The tread is supported ,m Another object is to provide a stairway step upon the upper edge oi` the riser il and an angle i@ having a very small number of structural parts in iron 22,'which extends from the end bar i2 to the its structure. end'bar I3. The underside of the tread is pro- Another object is to provide a moving stairway vided with a groove 23 which engages the angie step in which the riser or apron will serve not only 1'1'011 22 t0 prevent the tread from Working fer- `11; as an apron but will also serve as a support for the Ward 0r beCkWard- The angle irOl iS Slipperted 15 tread of the step and maintain its correct shape in position by Securing Orle end t0 a bracket 24 On without the use of a step frame. the upper portion of the end bar I3 by suitable A further object is to provide for obtaining bolts 25. The other end of the angle iron is sequietness in the operation of moving Stairway cured in a like manner to a bracket 2t on the steps when they are traveling without any load as upper portion of the end bar l2. The lower ends 2o well as when they are traveling with a load, of the bars l2 and i3 are provided with suitable A further object is to provide for absorbing the brackets 21 and 28 for Supporting the lower edge vibrations of a moving stairway step in one man- 0f the alOrOIl ner when it is traveling under no load and for HeretOfOre in CerlStrllCtirlg IrlOViIlg Stairway 25 absorbing the vibrations of the step in another Steps, 1t has been customary to provide a Step lz5 manner when it is traveling under a load, frame comprising a plurality of bars and brackets It is also an object to provide for the automatic bolted or melted together, but in practicing my transfer of the step from one vibration preventing inVentiOn, Provide er1 mprOVed Construction means 50 the other Vibration preventing means which eliminates 2t COIlSdI'&bl 3.1110111113 0f the when the load condition of the step changes. VibratiOD Usually inherent irl a Step Structure 0f 30 For a better understanding of the invention, @any PartS- TlflSy iS aCCOmplished by prOVidiHg reference may be had to the accompanying draw- Improved bearing SUDDOrtS and by eliminating mg, in which; part of the step frame and substituting therefor Figure 1 is a top plan View of a step for a moving an improved form of riser which acts as a portion stairway; of the step frame and as an apron for the step. 35 Fig. 2 is a view in rear elevation, partly in sec- AS Sl'lOWIl in FigS- 4 and 5, the apron I I common, of the Step Shown in Fig 1; prises a sheet 30, preferably of stainless steel, bent Fig. 3 is a view in right-hand end elevation of into a Slight upward Curve and ha'Vrlg itS upper the step shown in Fig 1; edge 3 I, its lower edge 32 and its end edges 33 and Fig. 4 is a view, taken from the interior of the 34 bent nWardly Substantially et right angles t0 40 step, of the riser or apron of the step; the face of the riser. The bent in end portions 33 Fig. 5 is a View in end elevation of the apron or and 34 DrOVide a Strengthening angie at each end riser 1mg-Hated in Fig; 4; for the riser plate so that it will be able to support Fig. 6 is an enlarged representation of the leftthe Step tread Witl'lellt bending. The UDI-'1er hand. front axle bearing of the step illustrated in bent 1n edge 3l 1s prcvlded with Small upwardly 45 Fig 2; extruded portions 36 disposed to enter a groove 31 Fig, 7 is an enlarged View in ond elevation of the in the underside of the tread Ii! to assist in holdlower portion of Fig. 5; and ing the tread in its correct position.

Fig. 8 is an emerged view, in section, of the A tapped bar 38 is spot Welded, as at points 39,

1owor left-hand portion of Fig, 3 showing the to the underside of the bent in edge 3l to act as a 50 joint between the lower end of the step riser and Stiffenng bar and to also provide a plurality of tap the yoke on which it is secured. holes 4I disposed to receive a plurality of screws 42 Referring more particularly to the drawing, I which pass through the tread l0 and hold it in have illustrated a moving stairway step as composition on the riser II. A lug 43 is disposed on prising a step tread I, an apron or riser II, a pair the inturned edge 32 of the riser at the left-hand 55 end mig. 4), and a lug 44 is disposed on the inturned edge 32 at the right-hand end of the riser. These lugs are spot welded to the inturned edge and are provided with bolt holes 45 and 46 by means of which they may be firmly bolted to the cooperating lugs 2'I and 23 on the end bars I2 and I3. The inturned edge 32 is also provided with downwardly extruded portions 48 and 49 disposed to be seated in cooperating grooves 5i] in the brackets 2l and 2S, respectively, at the lower ends of the bars I2 and i3 to aid in maintaining the riser plate in its correct position onY the end bars.

The lower edge of the riser plate is protected by a guard plate 53 which extends along the central portion of the inturned edge 52 and is securely riveted thereto by a plurality of rivets 54. The outer edge 55 of the guard plate 53 is bent downwardly to protect and complete the outer face of the riser I I.

By this construction,'it will be seen Vthat the step tread I0, the riser II, the angle iron 22 and the end bars I2 and I3 are secured inl such a manner as to provide a complete step structure of relatively few parts and yet a structure which is strongly and rmly held together by a small number of screws and bolts. It will also be seen that the smaller number of parts held together will reduce the amount of vibration in the step and thereby eliminate a source of noise usually present in the operation of moving Stairways.

Referring to the rollers on the step, the leading roller Iii is mounted upon the outer end of a front axle 6G andv is held in position thereon by a nut 5 I. The axle is mounted in an axle support 5'I on the front or upper portion of the end bar I2 and in an axle support bracket 52 attached tothe cross angle iron 22 by a bolt 63. The axle is held in the brackets 5l and 62 by resilient bushings 6G, preferably of rubber or similar material. A cotter pin 65 is disposed through a collar 66 on the axle 65 to prevent its movement to the left, and a similar cotter pin El and collar G8 are disposed adjacent to the bracket 52 to prevent the axle from moving to the right. The leading roller I5 at the right is mounted in the same manner as the leading roller just described.

The trailing roller I 6 is rotatably mounted upon the outer end of a stub axle 'EI and is secured thereon by a suitable nut l2. The stub axle is mounted in the trailing axle support 'I3 by means of a resilient sleeve 64a which is retained in position by a pair of suitable washers lli and 15. A nut 'I6 on the inner end of the stub axle holds the combination rmly in position. 'Ihe trailing roller I'I is mounted upon a stub .axle disposed in the trailing roller support I5 in the same manner as the stub axle for the trailing roller It is mounted in its support.

In the steps heretofore constructed, the resilient bushing 64 has been constructed usually of a solid resilient material, but in practicing my invention I provide a resilient bushing having two different surfaces for supporting the step in order to decrease its vibration and enable it to be operated Without the noise that usually accompanies moving stairway steps. By referring to Fig. 6, it will be seen that the bushing lid is provided with a no-load bearing surface comprising a pair of narrow circular ridges 8@ and SI extending entirely around the bushing to engage the inner Surface of the axle support bracket in which the bushing is mounted for the purpose of supporting the step while it is operating without load. The bushing is also provided with a load bearingy surface 82 of less diameter than the no-,load surface and which is disposed to receive and support the axle support bracket when the step is carrying a load such as that of a passenger. A groove 83 is disposed at each side of each of the ridges and 3i to provide room for the ridge of resilient material to spread or flow into when a load on the step bears the bracket downwardly to where it engages the load bearing surface 82. The bushing is also provided with a beveled end 85 to enable it to be easily positioned in the bracket during the assembling of the step parts. A shoulder 8l is disposed Von the other end of the bushing to provide a seat for the collar 66 through which the cotter pin 65 passes. Each axle support bracket is provided with a similar bushing, and it will be apparent that when the step is running with no load, the ridges 85 and 8l on each of the bushings will support the bracket on their thin outer faces and that the tendency for the step to vibrate in a disturbing manner will beV eliminated by reason of the light resilient support on which it rests. Itrwill also be apparent that when the step is loaded, as by a passenger standing thereon, the weight of the load will cause the brackets to overcome the slight resilient support of the ridges 55 and BI and move down to rest upon the face 82 of the central portion of the bushing, and that in this position the loaded step will be firmly but resiliently supported in such manner that practically all vibration because of its loaded condition will be eliminated, and, therefore, that the step will operate quietly and without any disturbing noise.

Although I have illustrated and Vdescribed only one moving stairway step embodying my invention, it will be obvious that 'many changes and d modications may be made therein without departing from the spirit and scope of the invention.

I claim as my invention:

1. A moving stairway step comprising a pair of end bars, a cross member connecting the front ends of the end bars, a curved sheet metal riser having its edges bent inwardly to a position substantially at right angles to its body, a brace bar secured to the inner upper surface of the lower rY tread, means for mounting the step tread with its front portion on the cross member and its rear portion supported solely on the riser, a plurality of rollers, and means for attaching the rollers to the end bars to support the step on a track.

2. A moving stairway step comprising a pair of end bars, a cross member connecting the front ends of the end bars, a curved sheet metal riser having its edges bent inwardly to a position'substantially at right angles to its body, a brace bar secured to the inner upper surface of the lower bent-in edge of the riser, a metal bar secured to the inner face of the upper in-turned edge of the riser, means connecting the lower edge of the riser to the rear ends of the end bars, a step tread, means for mounting the step tread with its front portion on the cross member and its rear portion supported solely on the riser, a plurality of rollers, means for attaching the rollers to the end bars to support the step on a track, and a downwardly extending protecting strip of metal secured to the lower iii-turned edge of the riser. y

3. A step for a moving stairway comprising a. pair of end bars, a cross member connecting the front ends of the end bars, a sheet metal riser connecting the rear portions of the end bars, said riser having its end edges bent inwardly to stiffen it vertically for preventing buckling and having its lower edge turned inwardly to provide a surface to engage the rear portions of the end bars and a short portion of its upper edge turned inwardly to provide a seat for a step tread and its upper bent-in edge having upwardly extruded portions, and a step tread having its front portion removably secured to the cross member and its rear portion removably secured to the upper edge of the riser and having indentations in the underside of its rear portion to t over the extion between the upper edge of the riser and the front ends of the cross member is the step tread, and removal of the step tread from the cross member and the riser permits entry to the interior of the stairway with no material interposed between the upper edge of the riser and the cross 10 member.

JAMES DUNLOP. 

